Combined indicator and limit switch actuator



y 12, 1932- H. E. HALLENBECK I 1,867,452

COMBINED INDICATOR AND LIMIT SWITCH ACTUATOR Filed Dec. 12, 1951 5Sheets-Sheet l Q ill-14m n! L j T R w- 0 I F I A N q I mm 5 "F." s g i vt i g N i i H E N 0 as 0 q v 23 INVENTOR ATTORNEY 1932- H. ETHALLENBECK1,867,452

COMBINED INDICATOR AND LIMIT SWITCH ACTUATOR Filed Dec. 12, 1951 3Sheets-Sheet 2 S mil" Ill. I! l y 12, 1932- H. E. HALLENBECK 1,867,452

COMBINED INDICATOR AND LIMIT SWITCH ACTUATOR Filed Dec. 12, 1951 3Sheets-Sheet 3 INVENTOR 4 f liflffallmad ATTORNEY Patented July 12, 1932units-o STATES PATENT oFFic-I:

HAROLD E. narnnunncn, or Henson, NEW YCEK, ASSIGNOR To eir ro'nn-wooncoir- PATTY, or nunsou, new YORK, A conronATron or new YORK COMBINEDIivnrcATon AND LIMIT SWITCH ACTUATOR This invention relates toimprovements in limit switches for electrically operated traversinghoists and among other objects, aims to provide a very simple andcompact limit switch actuator preferably, but not necessarily, combinedwith indicating means, and so constructed and arranged that the traversemotor is automatically stopped at the predetermined limits of travel ofthe load carrier operated by said motor. The invention particularly aimsto improve upon known trolley bucket systems by providing a motorcontrol unit of such few parts that it may be manufactured and installedvery economically, and hence may be sold at a low price; also to providea. unit rotatable for ease of adjustment and adaptability to varioustrav-.

ersing hoist installations. The invention has other objec'tswhichwillappear during the following description of the preferred embodimentthereof which is shown in the accompanying drawings.

In said drawings,-- 1 Fig. 1 is a plan view of. a motor-poweredtraversing hoist unit equipped with an actuator for limit switches;

Fig. 2 is an elevation, on a somewhat larger scale, of the mechanism fordriving the limit switches and indicating means;

F i g. 3 is a side elevation of the mechanism Fig. 2; and Figs. 4 and 5are vertical sections, at right angles to each other and both on thesame enlarged scale, of the limit switch casing and actuating parts. I

The motors of the described power unit are preferably used in anautomatic electric control system such. as is dc. cribcd and claimed inmy pending application, Ser. No. 491,53a, filed October 27, 1930.;although the invention will be equally useful in atrolley bucket systemcontrolled by hand. The wiring and connect-ions are such that the bucketis automatically hoisted, when loaded, to a point adjacent the undersideof'th e trolley, whereupon hoisting automatically stops and traversemovement in a predetermined direction begins. When the trolley-hasreached a point over thespot where the load of the bucket is tobedischa'rged, it is automatically Application filed December 12, 1931,Serial N5. 580,686.

stopped, and loweringofthe bucket automatically takes place. Dumping ofthe contents of the bucket is eiiected as soonas -the bucket strikes anobstruction, as disclosed the Bennett Patent llo. 1,7 l1,123 of December2st, 1929, and substantially instantaneous reversal of the bucket takesplace, so that the bucket starts up to the trolley as its loaddischarges. Ls soon, as the bucket reachesthe trolley, hoistingautomatically ceases, traverse begins and continues until the trolley isover the pointwhere the bucket is to be lowered for another load; thentraverse is stopped, the bucket is automatically lowered and brought toa stopat the loading point. I deferring particularly to Fig.1, there isshown a machine base on which all the parts to be described aresupported, so that the entire mechanism may be shipped and installed asa unit. Journaled in bearings 11 secured to the frame is a drum-shaft-12on which hoist drum 13 and trolley or traverse drum 14 are mounted forindependent rotation. Hoist drum 13 is loose on shaft 12 and is drivenby a gear 15 fixed thereto and meshing with a pinion 16 on acountershaft 17 journaled in bearings 18. Countershaft 17 is driven by agear 19 which meshes with motor pinion 20 of the hoist motor 21 which ison base 10. Obviously rotation jOf the hoist motor inopposite directionswill drive hoist drum 13 in opposite directions at a reduced speed,thereby winding or unwinding hoist cable 22 (which is dead-ended to thedrum) to raise or lower the bucket or other load carrier, not shown. I

The traverse or trolley drum 14 is fixed on shaft 12 and hence isrotated by gear 23 which is secured to said shaft. Gear 23 is driven bypinion 2 1 which is secured to gear 25 loosely mounted on countershaft17, and gear 25 is driven by pinion 26 of the traverse or trolley motor27 mounted on the base 10. Reverse rotation of motor 27 will obviouslyrotate drum 1 1 in opposite directions, at a reduced speed, to move thetraverse-cable 28 in opposite directions. On the shafts of the motors21, 27 are solenoid brakes 29, 30 re spectively, said brakes actingautomatically to stop the motors and hence the drums and cables wheneverthe power is cut 05 from the motors. In the aforesaid pendingapplication, I have shown means whereby power is automatically out offfrom and applied to the meters at the proper intervals.

As shown in Fig. 1, there is a sheave 31 mounted to rotate in a verticalplane on a sheave stand 32 secured to machine base 10, and the traverseor trolley cable 28, after being wrapped several times about drum 14, ispassed around sheave 31 and brought back around the drum 14 again. Thecable 28 extends upwardly to the trolley (not shown) to which its endsare lined, so that rotation of drum 14 in opposite directions will movethe trolley in opposite directions, thus moving the bucket, which issuspended from the trolley by the hoist line. It will be clear that thetrolley is moved solely because of friction between the cable 28 anddrum 14. This friction is enhanced by wrapping the cable around sheave31 and then bringing it back to and around the drum, as the cable tendsto hug the drum more tightly when passed at an intermediate point arounda sheave spaced from the drum shaft but parallel to the medial plane ofthe drum.

The sheave 31 is not only useful for increasing the frictional grip ofthe traverse cable on its drum; it is also used to drive the indicator(to be described) which shows the position of the trolley and also thelimit switch mechanism (to be described) which controls two limitswitches governing the traverse of the trolley through its motor 27, Asthe cable 28 drives sheave 31 by friction only, and as said cable isdirectly secured at both ends to the trolley, it follows that onlyactual movement of the trolley effects move ment of the trolleyindicator and of the trolley-governing limit switch actuatingmechanisms, which are driven only when sheave 31 is rotated. Therefore,slippage of the drum 14 relative to cable 28 may take place withoutaffecting the accuracy of the indicator and withoutalfecting the properworking (in point of time) of the limit switches. Only slippage ormovement of cable 28 relative to sheave 31 would make the indicator andlimit switches inaccurate. and such slippage or relative movement willnot occur except under extraordinary circumstances because the load onsheave 31 is very light, and cable 28 presses against it very tightly.

Referring to Figs. 2 and 3, which best show the indicator, it is seenthat sheave 31 drives a shaft 33 on which there is a bevel gear 34meshing with bevel gear 35 on a vertical shaft 36. WVhile an idler orrope driven sheave 31 is greatly to be preferred, for the illustrativetraversing hoist unit, it is within the scope of my invention to providea gear drive for shaft 33, and hence for shaft 36, which may be donewhenever the load carrier has no slippage relative to the drum whichoperates it, for example, when the indicator and limit switches are tobe used with a hoist drum. The vertical shaft 36 is enclosed in atubular housing 37 supported by a bracket 38 on the upper end of sheavestand 32, and said housing 37 provides a standard, fixed upon themachine base, by which the indicator or dial plate 39 and limit switchhousing 40 are supported. See, also, Fig. 1. Through a reductiongearing, to be described, vertical shaft 36 drives a horizontal shaft 41on which a pointer 42 is fixed, the pointer thus rotating slowly in onedirection or the other as the trolley moves back and forth on its track.By selecting the proper reduction gearing and arranging the indicia 43properly, it is clear that the position of the bucket may be ascertainedat any time in its traverse by noting the pointers position relative tothe dial.

Obviously, in the described embodiment,

the pointer will rotate not more than one revolution for the greatestpossible traverse of the bucket from the loading point; but if desired,the indicator may be of a different type. as like the indicator of theH. V. Harding Patent No. 1,705,973 dated March 19, V

1929, in which event the speed reduction need not be so. great, andtraverse over a large plant may be accurately indicated. For smallplants, however, the described embodiment is ideally fitted, as it isquite economical to make, install and maintain in service. As shaft 41is also a limit switch actuating shaft, it follows that the only eX- traparts necessary for the indicator are the pointer 42 and dial 39.

At the upper end of standard 37, a collar 44 fitting over said upper endis secured by a set screw 45 (Figs. 2 and 3), said collar thuspermitting rotation of the indicator assembly to turn the dial towardthe operators position, whatever it may be. Thus the indicator isadaptable to a wide variety of conditions without any change in its con-StlUCtlOIl.

Referring to Figs. 4 and 5, it is seen that the upper end of verticalshaft 36 is within the housing 40 and carries a worm 46 meshing withworm gear 47 fast on shaft 41, the pointer 42 being secured to shaft 41by a nut 48 and by parts to be described. Obviously, at the start oftraverse, the pointer should be at the zero position, but if not, thesheave 31 is rotated by hand, with cable 28 stationary, until thepointer is exactly at the Zero mark. Thus the indicator may be setaccurately without difficulty.

lVithin the casing or housing 40 are two limit switches 49 of standardconstruction, being supported by bracket 50 in such posi tion that theirpivoted switch arms 51 are moved by cams 52 which are fast to shaft 41.Preferably the cams 52 are of bakelite traverse motor. 10 i V i efl e ins ma anese fee t i ree i he r s 'b ly amend ng th im t weet. w th itind fie ti tefida pivoted switchfarms 51 are held pressed against theswitch contacts '53 springs 54 ex ept vlan earns 52 push them away w theem e asie h s' l ane of the sptrings, thus breaking the circ uit offtheI p v Each switc'h arm is insulated from the mac-seem and casing {l0 andhas a ciol'itactfhl which touches one of adjustable c' ont'ac t's whenthe'circuit controlledf said switch arm is closed. Contacts 53 'itrescfanimate for adjustrnent, so tlia't thecirouit may be properly brokenbyeach cam. Further details ,iof the limitswitchejs are not disclosedbecause "the specificconstrliction of said switches forms no partbfi'nyinvention.

Asf'sho'w'n, shaft-41 isjournaled in aushaped bearingbracketetisecuredto the bottom of housing 40. Each earn 52 isan-gularly adjustableupon and is secured to sli'aftitl by means which will now be described.Itestran e) thefl'efthand cam in-Fig. 5, there are screws 56 secured tosaid cam and passing ltlirough'spa c'in g 'niembersb'l', 58, beingparallel to shi'ftfl tl, Shaft tl carries two bushings 59, 60, bushing59 being fixed to the shaftand bu'sl'ii'n g 60 being loose-upon it, andboth bushings, 'having 'a-"circular end flange. The flange 'of bu'shing59 m serve-"to space cain-52(which surrdunds said bushing) fromtheadjacer'ltj'wall of the'be'aring bracket 55', as shown,thuspreve'nting movement of the cam in onediirection onthe shaft,'thespacing members 57, 58j an'd nut ls preventing move- "nhent "in "theor'rposit'e direction; It will also be clear that shaft &1 is preventedfrom moving ldng it'iidinallyin one direction by the end flange ofbushing 59. The flange of bushing 60 not only provides an abutment forthe outside spacing member 58 but also provides convenient means forsecuring the pointer 42 to bushing 60, this being done by screws 61.Both bushings are cut away at their meeting ends, as clearly shown, sothat bushing 60 may be locked against rotation relative to bushing 59(and hence relative to shaft 41) whenever said ends engage in the mannerillustrated. Such engagement is effected by tightening nut 48, whichthrusts bushing 60 along shaft 41 toward bushing 59. However, theangular position of the cam with respect to shaft l1 may be changed atany time by loosening nut 48, whereupon the assembly consisting of thetwo spacing members 57, 58 and cam 52 may be turned on said shaft. Thisoperation obviously varies the time at which the left-hand limit switchwill operate, and hence varies the amount of traverse of the loadcarrier in one direction.

Referring now to the construction at the right side of Fig. 5, it willbe clear that the right-hand cam 52 is adjustable relative to shaft-41inthe same manners-site left hand cam; shortpointer 62 is clamped'by nut'd3 to't'hepshaft, just as the 'long pointen fflis'; This short pointerprovides a convenient means for determining the'adjustmen t which hasbeen made at the othe'r side of the casing and will enable the operatorto "duplicate the adjustment on the'r'i'ght-handside. The p0 sition ofpointer 62 maybe marked-byiising V a sharp implement on spacingmem'ber5"8,*'or

said member may be initially marked with indicia, not shown, Thusbothcams maybe moved angularly as often as desired, until it is determinedby experiment that thyaefiu: ate the limit switches to bring the trolleyto a stop at theproper point. Obviously, the a'd justment of both camsis Very uickly and easily efi'ected. g p

The described construction is easily-iii stalled and adjustedandeconomical com bined indicator and limitsiv'itch actuator for a smalltrolley bucket plant. I

Obviously, the present invention not restricted to the particularembodiment thereof hereinshown an'ddescrib'ed. More0ver,'it is notindispensable that all the features of the invention'be used conjointly,sincethey may be employed advantageously in various combinationsandsub-combinations;

.1. A combined actuatorjfor limit switches and for anindicatorcomprising, in combination, ashaft driven through a reductiongearing; 'a pointer on the shaft; a pair of flimit switches -adjacentthe shaft; a p'air of cams carried onthe shaft in position to actt'i-'at-ez said limitsw'itchesf; and man anese to hold the pointer and alsomeetin immovable relative to the shaft, said'lnea'ns being] idiserrg'ageable to permit angular ad justinerit of-eachcam and also the-pointerrelativeto'the 'shaft.

I Ajcdmbified actuator for limit switches nd for anf'i ndicatorcomprising, in com;- bination, I a driven shaft; a worm on said shaft;'aworm gear driven bysaid worm"; a second shaft driven by said wormgear; said second shaft being screw-threaded at its o-p 'posite ends; anut on each end of the second then; a pair 'of'limit switches adjacentthe second shaft; a 'pair of spacedcanis carried on the 'second'shaft inposition toactuate said limit switches; a pair of pointers also on saidshaft; and means on the-shaft providing abutments against which the twocamsfa-nd the two pointers maybe pressed soas to clamp them to the shaftwhenever said nuts are tightened.

? 31 A combined actuator for limit switches and for an indicatorcomprising, incombin'ation, a driven shaft; awornfi on saidshaft'; aworm gear'driven by said wor a-"second shaft driven by said worm ge'amsafd'seegfid start bing screw threa'ded its opposite *encisg a nuton-each end of the second "shaft;

its

cams and the outer end flanges; the inner bushings being fast to theshaft and the outer bushings being interlocked with the inner bushingswhen the nuts are tightened.

4. An actuator for limit switches and for an indicator comprising, incombination, a shaft; means for driving the shaft at a very slow speed;a pair of bushings fixed to the shaft and having flanges at their innerends; a. pair of cams loose on said shaft, surrounding said bushings,and abutted against said flanges; a second pair of bushings slidable onsaid shaft but interlocked with the first pair so that they rotate withthe shaft, when in position; nuts screw-threaded on the 0pposite ends ofsaid shaft; and pointers secured to the outer ends of the second pair ofbushings, with the nuts located outside said pointers, so as to thrustsaid second bush ings inwardly when tightened.

5. An actuator for limit switches comprising, in combination, a shaft;means for driving the shaft at a very slow speed; a pair of cams atspaced points on said shaft; a pair of bushings secured to the shaftwith the cams surrounding them; a second pair of bushings on the shaftinterlocked with the first pair of bushings yet removable therefrom bypulling longitudinally of the shaft; a pair of nuts screw-threaded onopposite ends of said shaft; said nuts, when tightened, thrusting thesecond pair of bushings into interlocking engagement with the firstpair; said cams being individually clamped to the shaft when thecorresponding nuts are tightened.

6. An actuator for limit switches comprising, in combination, a casing;a U-shaped bearing bracket intermediate two opposite walls of thecasing; a shaft rotatably supportshaft supported by the, sheave standand driven by the sheave; a standard enclosing said shaft and supportedby the sheave stand; a worm on the upper end of the vertical shaft; aworm gear driven by the worm; a horizontal shaft driven by the workgear; a dial plate secured to said standard; and a pointer fixed to saidhorizontal shaft and movable over the face of the dial plate.

8. A unitary indicator comprising, in combination, a sheave; a sheavestand; a vertical shaft supported by the sheave stand and driven by thesheave; a standard enclosing said shaft and supported by the sheavestand; a casing rotatably supported at the top of said standard; a wormon the upper end of the vertical shaft, within said casing; a worm gearwithin the casing driven by said worm; a dial plate fixed to said casingon the outside; a horizontal shaft driven by said worm gear; and apointer fixed to said horizontal shaft'and movable on the face of thedial plate.

9. A unitary indicator comprising, in combination, a vertical standard;a powerdriven shaft within the standard; a casing; a collar fixed to theunderside of the casing and rotatably mounted on the upper end of thestandard; a set screw'holding the collar and casing in any desiredangular position; an indicator dial fixed to the casing; reductiongearing within the casing driven by said shaft; a second shaft withinthe casing driven at: a slow speed by said reduction gearing; and apointer secured to said second shaft and movable over said dial.

In testimony, that I claim the foregoing as my own, I have heretoafiixed my signature.

HAROLD E. HALLENBECK.

ed by said bearing bracket; a worm gear fixed V to the shaft between thetwo arms of said bearing bracket; a power-actuated worm for driving saidworm gear; bushings fixed to said shaft on each side of the bearingbracket and each having an end flange abutting against the outer wall ofthe bearing bracket;

a cam loosely surrounding each of said bushings; spacing means outsideof each cam but loose on said shaft; and nuts screw-threaded on each endof the shaft and clamping said cams on the shaft by thrusting the same,through the spacing means, against the aforesaid end flanges.

7. A unitary indicator comprising, in combination, a sheave; a sheavestand; a vertical

